Many biological experiments are designed and interpreted on the basis of presumed mathematical model, such as the Michaelis-Menten model of enzyme kinetics. In the part of biology and medicine which is related to chemistry (biochemistry, pharmacology, and physiology), many of the methods now available for using such models are either inaccurate or are so difficult to use that they are ignored. Our existing methods are subject to the latter criticism, but this problem can be relieved. We will perform the necessary investigations to formalize and automate, as far as desirable, our current modeling techniques, and use them to design experiments. This includes some simple operations not requiring a computer. There are six major operations involved in our present techniques. A number of computations are common on some of them. We will prepare computer programs to perfom these operations by adapting, modifying, or augmenting our existing software. These programs will be "friendly" and well-documented so that they will be easy to use and will require little knowledge of mathematics and computing. These programs may be used individually for modeling simple or small-scale systems. They will be mutually compatible and will constitute a broadly applicable modeling package. Some emphasis will be given to enzyme kinetics, as its principal operations, quantiative measurements and analysis of the results to select mechanisms and evaluate kinetic constants, actually constitute fitting a model to data.